| Appareils Ménagers Martin Électro Confort | Appliance Repair & Service | — |
| Appareils Ménagers Y T | Appliance Repair & Service | appareilsmenagersyt.com |
| Appareils Services Marad 01 | Appliance Repair & Service | facebook.com |
| Appartement 200 | Bars | twitter.com |
| Appartement Hotel Montreal | Apartment Hotels | appartementhotel.com |
| Appartement Meublé Montréal | Apartments | studiomeublemontreal.com |
| Appartement Sur La Main | Apartment Hotels | — |
| Appartements De Luxe Montréal Inc | Apartments | — |
| Appartements Le Jardin | Apartments | appartements-le-jardin.com |
| AppDirect Canada Inc | Information Technologies (IT) | — |
| Appealing Gardens | Landscaping | facebook.com |
| Apple Canada Inc. | Tout Entreprises et services, Tout Informatique et internet | apple.com |
| Apple Express Courrier Ltée | Tout Entreprises et services | appleexpress.com |
| Apple Repair Montreal | Tout Informatique et internet | applerepairmtl.com |
| Apple Sainte-Catherine | Answering Machines & Equipment | apple.com |
| Appliance repair | Appliance Repair | — |
| Appliance Services | Appliance Repair & Service | facebook.com |
| Appliance Specialist Inc | Appliance Repair | appliance-specialist.com |
| Applicad Inc. | Tout Informatique et internet | applicad.ca |
| Application Siriz | Boutiques | facebook.com |
| Applications Glue Inc, Les | Boutiques | facebook.com |
| Applications Mobiles Overview Inc | Shopping Mall | facebook.com |
| Applied Electronics Limited | Audiovisual Equipment & Supplies | appliedelectronics.com |
| Appnovation | Computer Consultants | appnovation.com |
| Apprendre Pour Comprendre | Camps | apprendrepourcomprendre.com |
| Approval Andy | Automobiles, car Dealers | — |
| APS | Associations | aps.org |
| APS Aviation Inc | Airlines | apsaviation.ca |
| Apsara | Massage Therapy | apsaramassage.com |
| ApSTAT Technologies | Information Technologies (IT) | apstat.com |
| Apstat Technologies Inc | Actuary Consulting & Services | apstat.com |
| APT 200 | Tout Bars et restaurants | apt200.com |
| Aptilon | Business & Trade Organizations | — |
| APY MTL | Computer Graphics Design & Animation | 3diweb.com |
| Aqral Association Québécoise Des Relieurs Et Des Artisans Du Livre | Bookbinders | — |
| Aqua Canada Appliances | Appliance Repair & Service | — |
| Aqua Massothérapie | Health and Beauty | — |
| Aqua Smoke | Cigar, Cigarette & Tobacco Manufacturers & Wholesalers | — |
| Aqua Viva | Plumbing | — |
| Aquababies | Aquariums & Supplies | facebook.com |
| Aquabrass Inc | Plumbing | aquabrass.com |
| Aquaduct Plumbing And Heating | Plumbing | — |
| Aquajet Restauration Inc | Tout Entreprises et services, Chemical & Pressure Cleaning Systems | nettoyagebrique.com |
| Aqualabo | Analytical & Testing Laboratories | — |
| Aqualara | Bikinis, Swimsuits & Swimming Accessories | aquadilara.com |
| Aqualine Plumbing Montréal | Plumbing | — |
| Aquanica | Tout Entreprises et services | aquanica.com |
| Aquarium Art | Aquariums & Supplies | aquariumart.ca |
| Aquarium H2O | Aquariums & Supplies | — |
| Aquarium Récifal Raging Reef | Aquariums & Supplies | ragingreef.com |
